Would you keep a Aggy GS412, or use DB410+GS212

May have a change to trade my GS412 for a DB410 at 8 I also have a GS412 that is also at 8.. So I could use my power amp crossover to power the 410s for lows and 212 for high...But I also would need a beefer power amp to do that since I think id only get 400watts per channel at 8..

Using a crossover for two cabs that are both built for full range isn't generally a good idea. The GS 10 cabs and 12 cabs do sound slightly different, so if you were hoping to get a little different tone or trying to shrink your cab size, then I could see trying the 410. Otherwise I think you'd just be shuffling cabs to get pretty much the same result.